1. Technical Field
The present invention pertains to isometric exercise devices. In particular, the present invention pertains to an isometric exercise system that serves as a computer system peripheral and facilitates user interaction with a host computer system while the user performs isometric exercises.
2. Discussion of the Related Art
Currently, a wide variety of different types of exercise devices are commonly utilized to promote health and fitness, particularly for people having sedimentary lifestyles and/or work environments, and to provide rehabilitation for particular types of injuries. The vast majority of these exercise devices utilize isokinetic and/or isotonic forms of exercise during operation, where a user's muscles are moved under resistance through a selected range of motion.
Isometric exercise is another effective form of muscular exercise that is very useful for rehabilitation, fitness and/or training. For example, isometric training is useful for fighter jet pilots who perform isometric muscular contractions of the lower limbs and body core during flights to prevent blackouts when subjected to high gravitational forces. Isometric exercise involves the exertion of force by a user against an object that significantly resists movement as a result of the exerted force such that there is substantially minimal or no movement of the user's muscles during the force exertion. Examples of simple forms of isometric exercise include pushing against a stationary surface (e.g., a doorframe or a wall), attempting to pull apart tightly gripped hands or to bend or flex a sufficiently rigid steel bar, etc. Due to their inherently tedious nature, isometric exercise devices are less popular and, accordingly, are limited in type and availability, in comparison to more conventional forms of isotonic and isokinetic exercise devices.
A particularly important feature in many isometric exercise devices is the ability to measure forces applied to a resistive object by one or more muscle groups. This is a basic component of biometrics. For example, U.S. Pat. No. 5,904,639 (Smyser et al.) discloses a device including a hand grip recording dynamometer with a load cell mounted therein. The load cell is coupled to a circuit board that is compressively squeezed during an exercise regimen. The device further includes a display to provide visual cues to a user prompting the user as to which hand to use and the amount of compressive squeezing force to be applied. U.S. Pat. No. 6,086,518 (MacCready, Jr.) discloses a similar type of device employing a squeezable exerciser having a body structure with squeezable surfaces and means associated with the body structure to produce reference signals as the level of force application reaches preset limits.
U.S. Pat. No. 4,742,832 (Kauffmann et al.) discloses an apparatus and method for measuring the strength of selected muscles of the human anatomy. The apparatus comprises an upright support frame with a force sensor and measuring device stationarily positioned on the frame. A first force transmitting member carries a patient engageable apparatus to transmit forces along a horizontal axis to actuate the sensor and measuring device. A second force transmitting member carries an additional patient engageable apparatus to transmit forces along a vertical axis, while a force transfer mechanism converts forces transmitted along the vertical axis into horizontal forces transmitted by the first transmitting member. The apparatus further comprises an apparatus for locating the patient in the same position during successive measuring sessions.
U.S. Pat. No. 6,296,595 (Stark et al.) describes an orthopedic restraining device including a housing with first and second distal end portions and restraining means for restraining movement of the first and second distal end portions with respect to each other. The restraining device further includes an elongated straining bar having a stress sensing mechanism for sensing stress on the restraining bar. A control unit, including a microprocessor and a recording mechanism, is provided for indicating sensed stress based upon outputs of the stress sensing mechanism. The elongated straining bar may include an adjustable hinge that is capable of adjusting the angle between the distal end portions.
U.S. Pat. No. 6,228,000 (Jones) discloses a machine for testing the muscle strength of a subject, wherein both static and dynamic strength tests are conducted on the subject. During the tests, forces exerted by the muscles are measured by devices that are connected to a computer and a display screen for displaying the strength of the muscles at different positions of a subject's body part. In the dynamic strength test, the subject moves a movement arm by exerting the muscles to be tested. The movement arm is connected to a resistance weight to oppose movement by the subject. In the static strength test, the movement arm is fixed in position and the subject exerts a body part against the movement arm upon exertion of the muscles to be tested. Force and angle measuring devices are connected to the movement arm and the computer for enabling the muscle strength to be displayed in terms of torque at various angular positions of the body part.
U.S. Pat. No. 6,325,767 (Wolff et al.) describes a strength measuring device for measuring the force-exerting ability of human muscle groups, where the device includes at least one vertically adjustable pressing element that works with a force-measuring unit which can measure the force exerted on the pressing element. The device further includes at least one additional pressing element that is also vertically adjustable and serves to hold certain parts of the test person's body in place.
The previously described exercising devices are limited in that they are tedious and provide limited feedback, generally relating to the amount of force being applied by the user operating the device. An isometric device that provides more enhanced feedback and is entertaining to the user is desirable to increase user interest in the particular isometric exercise so as to ensure continuous and sustained use of the device.
Accordingly, International Publication No. WO 91/11221 (Bond et al.) describes a computer controlled exercise system that sequentially and automatically implements isokinetic, isotonic and isometric exercises to permit a physical therapist to attend to other patients while the computer interacts with the patient to effect a desired therapy. In one embodiment, the motion of a patient's body, such as lifting or twisting the patient's limb, is converted into a runner on a display that competes against another runner. If the patient meets or exceeds the exercise goals, such as a number of repetitions or torque applied to the exercise unit, then the runner representing the patient will match or beat the other runner representing the goal.
Interaction between the exercise system and a computer in the previously described International Publication is limited to simple representations on a display that are based upon achieving set goals and do not provide an indication of the precise amount or degree of force being applied by the user to the exercise device at any given time. Further, this exercise system does not provide a virtual reality interactive environment, where the user is capable of interacting with a computer generated virtual reality scenario to control a variety of movements of a character or an object in the scenario as well as other features relating to the scenario. Those types of scenarios typically utilize a computer interface device to facilitate user interaction with the scenario. A majority of these devices employ strain-based measurement of force. For example, the pointing “nipple” employed in laptop computer system keyboards and the “Force-stick” utilized by high performance aircraft, such as fighter jets, employ strain-based technology. Further, this technology may be employed in various applications ranging from automotive to robotic interfaces. For examples of these applications, reference is made to U.S. Pat. No. 6,216,547 (Lehtovaara) and U.S. Pat. No. 6,388,655 (Leung).
In an attempt to combine virtual reality with an isometric exercise device, an Interactive Video Exercise System (IVES) is disclosed in Dang et al. “Interactive Video Exercise System for Pediatric Brain Injury Rehabilitation”, Proceedings of the RESNA 20th Annual Conference, June 1998. This system provides an instrumented video-game-enhanced exercise program for pediatric brain injury patients, where the system includes an isometric test apparatus, a data processing circuit box, and a Super NES™ system with an adapted game controller. The isometric test apparatus includes a first load cell rigidly mounted onto a metal cross-bar that clamps to two rear legs of a chair. A high tensile cable and an ankle band couple the shank of a subject sitting in the chair to the first load cell. A second load cell is mounted between two aluminum plates which rest on the floor. The subject's foot rests on the top plate against a heel stop and is secured with two straps. Isometric extensions of the subject's knee is measured by the first load cell, and isometric ankle dorsiflexion of the subject is measured by the second load cell. The signal from either load cell is transmitted to the data processing box, where it is processed and compared with a variable threshold value set by a potentiometer. When the transducer's signal exceeds the threshold value, voltage is passed to the adapted game controller whereby the selected operation is executed in a game (e.g., move right, move left, move up, move down, etc.). As a result, the subject can only play the game by performing certain isometric exercises.
The previously described IVES system is limited in that a game controller for a Super NES™ system must be adapted to render the system operable. In other words, the IVES system does not have flexibility for use with computer games associated with other computer systems that are incompatible with a Super NES™ system. In addition, the IVES system is limited to isometric knee and ankle exercises and, thus, is incapable of being utilized in a variety of different contexts where it is desirable to exercise upper body parts alone or in combination with lower body parts of a user.